Compasses



H. PERROT.

COMPASSES. APPLICATION FILED DEC-29, I919.

Patented Sept. 1

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A a/r1 r 12% Pumr T all whom itmay concern-1 Patented Sept. 1%, 1922.

entree s ares HEINRICH PERROT,OF' GALW, GEERBMNY.

' comrassns.

Application filed mem er as, 1919 Serial No. 348,228.

Be it known thatLiHmnnlcrr "citizen of the German Republic, andresident of Calw, Wurttemberg, Germany, have position.

invented certain new and useful Improve- 'ments in Compasses, of which the following is a specification.

The present 1 "vention relates to instruments such as compasses, dividers, scribers and the l ke comprising two pivotally-con- 'nected legs or 'membe rs and its object,

stated briefly, is the provision of improved "means for retaining, the legs or members of the instrument in adjusted position and,

when one of such legs is of two-part construction, for effecting afine adjustment of the outer part relatively to the fixed inner art. p According to the invention, the enlarged disk-shaped portions or' heads of the cornpass members which are arranged face to face and through which the pivot pinipasses in the usual manner, are conjointly formed with a wedge-shaped peripheral edge for coaction with apresser piece'having a complemental wedge-shaped edge, the arrangement being. such that the pressureexerted .upon the presser piece. by an adjusting device will be transmitted' to the two coacting wedge surfaces, with the result thatthe compass'members will be securely c'lamped 'n The fine adjustment of j, the two part member is effected, according to the invention, by means" of a micrometer screw which operat-ively engages with the movablefpart of said member and ispivotally car'rifedby the fixed part thereof, so that it. can be utilized first 'to shift the first-named part into the required positionj'and thereafter to lock itself in engagement with said part to prevent its accidental displacement.

An embodiment of the inventiorr is illustrated in the accompanying drawing, in which:

Figure 1 is a face view of a compass constructed in accordance with the invention;

Figs. 2 and 3 are part-sectional detail views at right angles to each other, showing the clamping device, and

Figs. 4 and 5 are, respectively, a side elevation and a vertical sectional View of the fine-adjustment device.

Referring more particularly to the drawing, a and b designate the two main members or legs of the compass, and 0 the pivot \vhich passes throughregistering central Pmmor, a

openings in the disk-shaped enlargements or heads 71 v at the upper endsof said legs, the

two heads having their inner faces disposed in abutting relation, as usual. The leg at is inja point d; but the leg I) is made in two parts and comprises a movable part or arm f which is centrally pivoted as at g to the lower end of the upper fixed partor leg proper b, the said arm f terminating at its lower-fend in a point e. I 3 The improved clamping means or device whereby the compass members are retained in adjusted position, comp-rises two co-acting companion parts, one of which consists of the 'two, heads h, the other part being constituted by a presserpiece which is shifted toward or from the adjacent edge of the heads byia screw m rotatably fitted in an internally threaded socketli The latter is held in place by a guides which is pushed over it and to which there is fixed a pairof fingers t. suitably connected to the members av and b and having a certain amount of play relative thereto. The confronting edges of the. two companion parts it and k are provided with complemental wedge-shaped surfaces for direct coaction with each other, one of such surfaces taking the form of a V-groove and the other of a V-shaped projection fitting therein. In the construction illustrated, the groove is formed conjointly in the edges of the two heads h and is indicated at-i; but it will be understood that it may be formed instead in the edgeof the presser part 70, in. which case the edges of said heads will be beveled to conjointly form'the- V -projection. In the present construction, the edgeof the presser piece fits in the V-groove i-z', as shown; and

the inward movement of said p resser piece, produced by means of screw .m will have the effect of binding the coacting wedge surof 'one-piece construction, and terminates edges of said head and 19 which are thus made of half length sdt'o" speak, and are arranged in such a manner as to fit between the screw and the com or member 6, as will be understood pass lgg from ig. 5; this arrangement enabling" the 7 ready assembling of the parts and their disassembling when necessary. The pivotal mounting of the screwcarrying' plate on the pin or screw 9 enables a slight rocking'move mentor said plate and a consequent rocking movement 'ofscrew a, which latter thereby locks itself tothe teeth 7 on arm f, and thus holds said arm in adjusted position;

I elaimas' my invention? v I. A compass or analogous instrument comprising a pair of legs having enlarged 'uppe'r'ends' or heads which are pivotally connected together; and a clamping device for said legs embodying a presser piece having an edge cooperative with the adjacent edges of said heads, and an actuating member 'for the presser p ece, the cooperating presser p ece hav ng "complm'ental wedge-sha ed surfaces for direct engagement with each other. i

compass or analogous instrument, comprisin a pair of legs having enlarged upper ends Lorheads which are pivotally connected together; and a clamping device for said legs embodying a 'p-resser piece having an edge cooperative with the adjacent edges of said heads, and an actuating member for the presser piece,- one of such cooperating edges forming a: wed eshaped groove, nd the other edge'forming a wedgeshaped projection to fit therein.

, compass or analogous instrument, comprising a pair of legs having enlarge-d upper ends'or heads which are foivot al'ly connected together; and a clamping device for said legs embodying a pressfer piece having. a wedge-shaped edge forcoop'era'ti'on with the adjacent edges of the heads, and an actuating screw for forcing the p rie'sser piece toward said heads to engage their cooperating edges.

7 i. A compass or analogous instrument,

nected together and the ed es of which conjointly form a V-shaped groove; and a clamping device for said legs embodyin a presses piece having V-shaped Jec'ge adapted toenter said groove, and means for fcrcingsaiid pr'esser piece towards said heads.

6. In a compass, the combination of a pai'rigcf pivotaHy-iconnected legs, one of which embodiestwo parts movable with respect to one another", one part having teeth an itsuppe'r end; and a fine adjustment de ice forfs'aid' part comprising a plate pivoted to the other part and provided with a pair cf bearings, and a or worin jou'rnaled in said bearings and engaged with said teeth, the pivotal movements of said plate locking said screw in such engagement so as to hold the parts against relative'displacement. I x

I a pmpass'the combination of apair of' pi'yotal'ly'c'onnec'tedlegs, one of which embodies" two parts" movable with respect to onefano'ther one part beingpivoted centrally mum other part and having its upper end C'il't' at an incline to form half l'ength worm teeth; and a fine adjustment device for said part comprising a micrometer screw or rock thefirst named part about its'pivot and subseqnentlyfengage said worm teeth tors'ionally and thereby hold said parts against relative displacement.

Signed Stuttgart, Wurttemberg, Germany this 13th day of- October. A. Di 1921.

HEINRICH PERROT; Witnesses:

Fig. Kmjnzsn'.

micrometer screw, 

